Information handling devices, such as laptop computers, tablet computers, smart phones and the like, typically have power states that attempt to manage a device's power consumption. A device conventionally provides one or more lower powered states that the user may transition to in order to save power.
The Advanced Configuration and Power Interface (ACPI) specification provides an example of a standard for device configuration and power management. The ACPI specification includes the following states. The S0 (or G0) state for when the device is up and running (full power). The G1 or “sleeping state” includes four sub-states S1-S4, as follows. The S1 state is a state in which the CPU stops executing instructions; however, the power supply to the CPU and RAM is maintained, while any devices that are not set to always on are powered down. The S2 state is similar to S1 state; however, the power to the CPU is off. The S3 state, sometimes termed “sleep”, “standby”, or “suspend to RAM”, is a state in which RAM remains powered, but some additional components may be powered down as compared to S2. The S4 state, sometimes referred to as “hibernation” or “suspend to Disk”, is a state in which content of memory is saved to non-volatile memory (normally to a hard drive or Flash), and the memory is powered down. S5 (G2) is a “soft off” state in which the device is completely powered down save a few select components that remain powered so the computer can “wake”. The G3 or “mechanical off” is a state in which the device is consuming almost no power (conventionally a clock remains powered using a separate power source).